Embodiments of the present invention relate to integrated circuit (IC) packaging technology and more particularly to improving connections between a substrate and a socket or other device.
Today's ICs are manufactured with increasingly higher performance, reduced costs, and increased miniaturization of components and devices. Accordingly, packaging for such ICs is also subject to ongoing shrinkage of form factors.
Some ICs such as processors, controllers, logic devices, memory devices and the like may be housed in a package including a substrate having internal electrical connections and other components. The package includes electrical connections to enable the package to be electrically connected to, for example, a socket that may be adapted on a circuit board such as a motherboard or the like.
One such packaging technology is known as a land grid array (LGA). A LGA package is a flip-chip (FC) package that includes one or more semiconductor die that are adapted within the socket, e.g., mounted on a substrate land carrier. An external surface of the substrate of the package includes a plurality of electrical contacts which are to mate with corresponding contacts in a LGA-type socket, while the other side of the package may be used as a mating surface for a thermal solution such as a heat sink.
As semiconductor devices shrink, so too do their packaging. While smaller size devices can be more efficiently and cheaply manufactured, size reductions in three dimensions can cause certain issues. For example, when a package shrinks in thickness, the package can become warped during various processing steps. Such warpage can affect the quality of electrical contact between the package and its intended mating surface within a system.
Furthermore, as devices include more and more functionality, additional electrical contacts are needed. To incorporate all the desired contacts, the size of the contacts, also referred to as land pads in a LGA implementation, decreases and the pitch or distance between pads also decreases. As these sizes and pitches decrease, so too do the corresponding contacts of a socket. In some implementations, these socket contacts are stamped metal contacts that may suffer from poor electrical connection, as the working range of these contacts becomes too small to compensate for warpage of a package post assembly. Such improper connection can lead to reduced performance or rejects if such connections fail to meet burn-in or other post-assembly tests.